Code cleanup.

Assets/Cryville/Common/Pdt/PdtExpression.cs

@@ -27,6 +27,16 @@ namespace Cryville.Common.Pdt {
 			}
 			return r;
 		}
+		/// <summary>
+		/// Patches an expression with a lefthand variable and a compound operator.
+		/// </summary>
+		/// <param name="target">The name of the lefthand variable.</param>
+		/// <param name="op">The name of the compound operator.</param>
+		/// <param name="exp">The expression.</param>
+		public static void PatchCompound(int target, int op, PdtExpression exp) {
+			exp.Instructions.AddFirst(new PdtInstruction.PushVariable(target));
+			exp.Instructions.AddLast(new PdtInstruction.Operate(op, 2));
+		}
 	}
 	internal abstract class PdtInstruction {
 		internal abstract void Execute(PdtEvaluatorBase etor);